Proteolytic patterns of head and neck squamous cell carcinoma

The significance of plasminogen activators and matrix metalloproteases for clinical outcome, growth and metastatic behavior of head and neck squamous cell carcinoma (SCC) is still controversial. The majority of studies has been based on either immunohistological stainings, which provide only limited quantitative information, or in vitro experiments. We analyzed 44 head and neck; SCC and 11 mucosa tissue samples for the expression of gelatinolytic or fibrinolytic proteases by quantitative zymographic analysis and compared lytic activities to clinical and histopathological data. We calculated activation ratios for matrix metalloproteinases-2 and -9 (MMP-2 and MMP-9) by separate evaluations of inactive and activated MMP forms. Increased gelatinolytic and fibrinolytic activity was found in head and neck SCC when compared to mucosa. Increased values were caused by MMP-9 and urokinase type plasminogen activator, respectively. No statistically significant correlations of either protease lytic activity or activation ratio could be related to T-stage, metastasis, tissue necrosis or the differentiation stage of tumors. The data recorded are compared with previously published reports.